Was intending to wait for the Oly 40-150 but the smaller size of the Panny is appealing. As is the current availability. And, I like the option of using in lens stabilization since I could easily see myself buying a Panasonic body at some point. I'm curious about user experiences with focus speed on the CDAF only Oly bodies, specifically the E-M5. Does it compare with lenses like the 12-50 in terms of focus speed, or is it noticeably slower? Also, any CA issues on and Oly body?